Recently, in line with the demand of the day, the necessity for safety against the failure of a power conversion system has been increasing, with the result that research into the diagnosis of the aging of power conversion systems has been actively conducted and the results of the research have been presented in various documents.
Methods presented in recent documents focus on the determination of the cause or state of a failure after the failure has occurred in such apparatuses.
Such methods include a method of estimating the abnormality of a conversion device module or equipment through the signal processing of input current and the spectral analysis of an operating frequency, and a method of extracting some of various variables related to the abnormality of a power semi-conductor switch or the abnormality of a controller, a filter capacitor, or an output stage, analyzing the signals, and presenting abnormality results.
Korean Patent Application No. 10-2003-0072963, filed on Oct. 20, 2003 in Korea, published on Apr. 25, 2005, and entitled Apparatus for diagnosing state of power conversion system, is an example of the representative results of research into a method of diagnosing the aging or degradation of a power conversion system. This diagnosing method is configured to analyze the voltage signals of the input and output terminals of a power conversion system or monitor variation in the capacitance of a filter capacitor and variation in ripple voltage, thereby being able to monitor the erroneous operation or damage of the power conversion system and monitor and diagnose an abnormal situation attributable to the aging or degradation of the apparatus in advance.
Furthermore, Korean Utility Model Registration No. 20-0399135, filed on Aug. 7, 2005 in Korea, registered on Oct. 12, 2005, and entitled UPS using individual battery management device, presents a scheme capable of optimally charging and discharging the battery of a power conversion system, such as a UPS, and managing the internal characteristics thereof.